Fun fact, for the greeks, 1 is not a number either - they said the natural numbers started at 2 and unity is something else. This is because, they said, all numbers represent pluralities.
The limit of the division function under certain conditions is not the same as division - division has a discontinuity at 0 which is expressing the same thing.
Defining division by zero only works if you don’t care to preserve the field axioms, which is often inconvenient and so not done. The Riemann sphere is not a field, and fairly niche in the context of mere division, so I stand by my accusation of this being misleading.
The policy of not defining division by zero to preserve the cancellation law is the most sensible default.
In the history of mathematics, -1 was understood waaaay before 0.
For the Greeks, doing 1-1 would be invalid, something close to dividing by zero for us.
Fun fact, for the greeks, 1 is not a number either - they said the natural numbers started at 2 and unity is something else. This is because, they said, all numbers represent pluralities.
Dividing by zero is well understood and sometimes even well defined.
That’s a stretch.
We know the limit of it and on a Riemann sphere it is defined as infinity.
We know the limit of a/x as x --> 0 if a ≠ 0.
The limit is different if a = 0.
The limit of the division function under certain conditions is not the same as division - division has a discontinuity at 0 which is expressing the same thing.
Defining division by zero only works if you don’t care to preserve the field axioms, which is often inconvenient and so not done. The Riemann sphere is not a field, and fairly niche in the context of mere division, so I stand by my accusation of this being misleading.
The policy of not defining division by zero to preserve the cancellation law is the most sensible default.